Decreased plasma adiponectin concentrations in women with gestational diabetes mellitus

Adipose stem cells-derived small extracellular vesicles transport Thrombospondin 1 cargo to promote insulin resistance in gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a highly prevalent disease and poses a significant risk to the health of pregnant women. Abdominal adipose tissue (AT) contributes to insulin resistance (IR) associated with GDM. However, the underlying mechanisms remain unclear.

METHODS

In this study, we developed a mouse model of GDM by subjecting mice to a high-fat diet. We collected adipose-derived stem cells (ADSCs) from the abdominal and inguinal regions and examined their role in inducing IR in normal tissues through the secretion of small extracellular vesicles (sEVs). The sEVs derived from ADSCs isolated from GDM mice (ADSC/GDM) were found to inhibit cell viability and insulin sensitivity in AML12, a normal mouse liver cell line.

RESULTS

Through proteomic analysis, we identified high levels of the thrombospondin 1 (Thbs1) protein in the sEVs derived from ADSC/GDM. Subsequent overexpression of Thbs1 protein in AML12 cells demonstrated similar IR as observed with ADSC/GDM-derived sEVs. Mechanistically, the Thbs1 protein within the sEVs interacted with CD36 and transforming growth factor (Tgf) β receptors in AML12 cells, leading to the activation of Tgfβ/Smad2 signaling. Furthermore, the administration of LSKL, an antagonistic peptide targeting Thbs1, suppressed Thbs1 expression in ADSC/GDM-derived sEVs, thereby restoring insulin sensitivity in AML12 cells and GDM mice in vivo.

CONCLUSIONS

These findings shed light on the intercellular transmission mechanism through which ADSCs influence hepatic insulin sensitivity and underscore the therapeutic potential of targeting the Thbs1 protein within sEVs.

Maternal first trimester metabolic profile in pregnancies with transposition of the great arteries

BACKGROUND

Higher maternal body mass index (BMI) and abnormal glucose metabolism during early pregnancy are associated with congenital heart defects in the offspring, but the exact mechanisms are unknown.

METHODS

We evaluated the association between maternal first trimester metabolic profile and transposition of the great arteries (TGA) in the offspring in a matched case-control study with 100 TGA mothers and 200 controls born in Finland during 2004-2014. Cases and controls were matched by birth year, child sex, and maternal age and BMI. Serum samples collected between 10- and 14-weeks of gestation were analyzed for 73 metabolic measures. Conditional logistic regression was used to assess the risk for TGA in the offspring, and a subgroup analysis among mothers with high BMI was conducted.

RESULTS

Higher concentrations of four subtypes of extremely large very-low-density lipoprotein (VLDL) particles and one of large VLDL particles were observed in TGA mothers. This finding did not reach statistical significance after multiple testing correction. The pooled odds ratio (OR) of the all metabolic variables was slightly higher in TGA mothers in the subgroup with maternal BMI over 25 (OR 1.25) and significantly higher in the subgroup with maternal BMI over 30 (OR 1.95) compared to the original population (OR 1.18).

CONCLUSIONS

Our findings indicate that an abnormal maternal early pregnancy metabolic profile might be associated with TGA in the offspring, especially in obese mothers. A trend indicating altered VLDL subtype composition in TGA pregnancies warrants further research.

Adiponectin DNA methylation in South African women with gestational diabetes mellitus: Effects of HIV infection

DNA methylation is increasingly recognized as a potential biomarker of metabolic disease. However, there is limited information on the impact of human immunodeficiency virus (HIV) infection on the candidacy of DNA methylation to serve as molecular biomarkers. This study investigated the effect of HIV infection on DNA methylation patterns in the peripheral blood of South African women with (n = 95) or without (n = 191) gestational diabetes mellitus (GDM). DNA methylation levels at eight CpG sites in the adiponectin gene (ADIPOQ) promoter were measured using bisulfite conversion and pyrosequencing. Differences between HIV negative (^-) and positive (⁺) women were observed. In HIV^- women, methylation at CpG -3400 was lower in GDM⁺ women compared to those with normoglycemia (8.5-fold; p = 0.004), and was associated with higher fasting glucose (β-co-efficient = 0.973; p = 0.006) and lower adiponectin (β-co-efficient = -0.057; p = 0.014) concentrations. These associations were not observed in HIV⁺ women. In silico analysis showed that Transcription Factor AP2-alpha is able to bind to the altered CpG site, suggesting that CpG -3400 may play a functional role in the regulation of ADIPOQ expression. Our findings show that DNA methylation differs by HIV status, suggesting that HIV infection needs to be taken into consideration in studies exploring DNA methylation as a biomarker of GDM in high HIV prevalence settings.

Diabetes during Pregnancy: A Maternal Disease Complicating the Course of Pregnancy with Long-Term Deleterious Effects on the Offspring. A Clinical Review

In spite of the huge progress in the treatment of diabetes mellitus, we are still in the situation that both pregestational (PGDM) and gestational diabetes (GDM) impose an additional risk to the embryo, fetus, and course of pregnancy. PGDM may increase the rate of congenital malformations, especially cardiac, nervous system, musculoskeletal system, and limbs. PGDM may interfere with fetal growth, often causing macrosomia, but in the presence of severe maternal complications, especially nephropathy, it may inhibit fetal growth. PGDM may also induce a variety of perinatal complications such as stillbirth and perinatal death, cardiomyopathy, respiratory morbidity, and perinatal asphyxia. GDM that generally develops in the second half of pregnancy induces similar but generally less severe complications. Their severity is higher with earlier onset of GDM and inversely correlated with the degree of glycemic control. Early initiation of GDM might even cause some increase in the rate of congenital malformations. Both PGDM and GDM may cause various motor and behavioral neurodevelopmental problems, including an increased incidence of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Most complications are reduced in incidence and severity with the improvement in diabetic control. Mechanisms of diabetic-induced damage in pregnancy are related to maternal and fetal hyperglycemia, enhanced oxidative stress, epigenetic changes, and other, less defined, pathogenic mechanisms.

No Association Between ADIPOQ or MTHFR Polymorphisms and Gestational Diabetes Mellitus in South African Women

PURPOSE

Gestational diabetes mellitus (GDM) is a growing public health concern. GDM affects approximately 14% of pregnancies globally, and without effective treatment, is associated with short- and long-term complications in mother and child. Lower serum adiponectin (ADIPOQ) concentrations and aberrant DNA methylation have been reported during GDM. The aim of this study was to investigate the association between the ADIPOQ -11377C>G and -11391G>A, and methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms and GDM in a population of black South African women.

MATERIALS AND METHODS

DNA was isolated from the peripheral blood of 447 pregnant women with (n=116) or without (n=331) GDM, where after ADIPOQ (rs266729 and rs17300539) and MTHFR (rs1801133) polymorphisms were genotyped using TaqMan Quantitative Real-Time PCR analysis.

RESULTS

Women with GDM had a higher body mass index (p=0.012), were more insulin resistant (p<0.001) and had lower adiponectin levels (p=0.013) compared to pregnant women with normoglycemia. Genotypic, dominant and recessive genetic models showed no association between ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms and GDM. Intriguingly, the risk G allele of ADIPOQ rs266729 was associated with higher fasting glucose and insulin concentrations, while the T allele in MTHFR rs1801133 was associated with higher fasting insulin concentrations only.

CONCLUSION

ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms are not associated with GDM in a population of black South African women. These findings suggest that these single nucleotide polymorphisms (SNPs) do not individually increase GDM risk in the African population. However, the role of these SNPs in possible gene-gene or gene-environment interactions remain to be established.

The Role of the Adipokines in the Most Common Gestational Complications

Adipocytokines are hormonally active molecules that are believed to play a key role in the regulation of crucial biological processes in the human body. Numerous experimental studies established significant alterations in the adipokine secretion patterns throughout pregnancy. The exact etiology of various gestational complications, such as gestational diabetes, preeclampsia, and fetal growth abnormalities, needs to be fully elucidated. The discovery of adipokines raised questions about their potential contribution to the molecular pathophysiology of those diseases. Multiple studies analyzed their local mRNA expression and circulating protein levels. However, most studies report conflicting results. Several adipokines such as leptin, resistin, irisin, apelin, chemerin, and omentin were proposed as potential novel early markers of heterogeneous gestational complications. The inclusion of the adipokines in the standard predictive multifactorial models could improve their prognostic values. Nonetheless, their independent diagnostic value is mostly insufficient to be implemented into standard clinical practice. Routine assessments of adipokine levels during pregnancy are not recommended in the management of both normal and complicated pregnancies. Based on the animal models (e.g., apelin and its receptors in the rodent preeclampsia models), future implementation of adipokines and their receptors as new therapeutic targets appears promising but requires further validation in humans.

Placental Regulation of Energy Homeostasis During Human Pregnancy

Successful pregnancies rely on sufficient energy and nutrient supply, which require the mother to metabolically adapt to support fetal needs. The placenta has a critical role in this process, as this specialized organ produces hormones and peptides that regulate fetal and maternal metabolism. The ability for the mother to metabolically adapt to support the fetus depends on maternal prepregnancy health. Two-thirds of pregnancies in the United States involve obese or overweight women at the time of conception. This poses significant risks for the infant and mother by disrupting metabolic changes that would normally occur during pregnancy. Despite well characterized functions of placental hormones, there is scarce knowledge surrounding placental endocrine regulation of maternal metabolic trends in pathological pregnancies. In this review, we discuss current efforts to close this gap of knowledge and highlight areas where more research is needed. As the intrauterine environment predetermines the health and wellbeing of the offspring in later life, adequate metabolic control is essential for a successful pregnancy outcome. Understanding how placental hormones contribute to aberrant metabolic adaptations in pathological pregnancies may unveil disease mechanisms and provide methods for better identification and treatment. Studies discussed in this review were identified through PubMed searches between the years of 1966 to the present. We investigated studies of normal pregnancy and metabolic disorders in pregnancy that focused on energy requirements during pregnancy, endocrine regulation of glucose metabolism and insulin resistance, cholesterol and lipid metabolism, and placental hormone regulation.

The association of maternal obesity and race with serum adipokines in pregnancy and postpartum: Implications for gestational weight gain and infant birth weight

Adiponectin and leptin are hormones known to play roles in maternal metabolism during pregnancy. Levels of these hormones have been demonstrated to vary based on adiposity and race. However, there is a lack of data concerning the relationship between race and the change of adiponectin and leptin throughout pregnancy. The purpose of this study was to examine serum levels of adiponectin, leptin, and leptin-to-adiponectin ratio (LAR) throughout pregnancy and to assess their association with gestational weight gain (GWG) and infant birth weight while considering the effects of race and pre-pregnancy body mass index (BMI). Serum levels of adiponectin, leptin, gestational weight gain, and infant birth weight were measured in 80 pregnant women at early (12.4 ​± ​1.3 weeks gestation), mid (20.6 ​± ​1.3 weeks gestation), late pregnancy (29.2 ​± ​1.4 weeks gestation), and 7-11 weeks postpartum (8.8 ​± ​0.8 weeks). In women overall, serum adiponectin decreased across pregnancy and increased at postpartum (p ​= ​0.17.) At each prenatal timepoint, both black race and obesity were associated with lower adiponectin (ps ​< ​0.05). In women overall, serum leptin increased across pregnancy, and declined at postpartum. At every assessment, a stepwise increase in leptin was observed in relation to BMI class. Black women with obesity had markedly higher LAR in mid- and late pregnancy and postpartum than all other groups (p ​< ​0.05). Serum leptin during pregnancy was significantly associated with total GWG in both black and white women (ps ​< ​0.005). Neither adiponectin, leptin, nor LAR were associated with infant birth weight. Race and BMI both have significant effects on serum adiponectin, leptin, and LAR levels in pregnancy and postpartum. Notably, the combined effects of race and BMI result in markedly higher LAR among black women with obesity. Implications for racial disparities in metabolic syndrome and postpartum weight retention remain to be explicated.

Insulin-Independent Reversal of Type-1 Diabetes Following Transplantation of Adult Brown Adipose Tissue Supplemented With IGF-1

As our previous publications show, it is feasible to reverse type 1 diabetes (T1D) without insulin in multiple mouse models, through transplantation of embryonic brown adipose tissue (BAT) in the subcutaneous space. Embryonic BAT transplants result in rapid and long-lasting euglycemia accompanied by decreased inflammation and regenerated healthy white adipose tissue, with no detectable increase in insulin. To translate this approach to human patients, it is necessary to establish practical alternatives for embryonic tissue. Adult adipose tissue transplants or BAT-derived stem cell lines alone fail to reverse T1D. A likely reason is transplant failure resulting from lack of growth factors abundant in embryonic tissue. Adding growth factors may enable transplants to survive and vascularize as well as stimulate adipogenesis and decrease inflammation in the surrounding host tissue. Previous data points to insulin like growth factor 1 (IGF-1) as the most likely candidate. Embryonic BAT abundantly expresses IGF-1, and embryonic BAT transplant recipients exhibit increased plasma levels of IGF-1. Therefore, we tested the ability of temporary administration of exogenous IGF-1 to enable adult BAT transplants to correct T1D.

Methods

Fresh BAT from healthy adult CB7BL/6 donors were transplanted in the subcutaneous space of hyperglycemic nonobese diabetic recipients. Exogenous IGF-1 was administered daily for a week following transplant, at 100 µg/kg SC.

Results

Adult BAT transplants with IGF-1 supplementation produced rapid long-lasting euglycemia at a 57% success rate, in contrast with no recovery in the control groups who received adult BAT alone, IGF-1 alone, or no treatment.

Conclusions

Temporary supplementation with IGF-1 enables adult BAT transplants to correct T1D phenotypes independent of insulin, providing a possible route to translate this treatment to human patients.

The role of adipokines in the pathogenesis of gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a complex condition whose physiopathology to date has not been completely clarified. Two major metabolic disorders, insulin resistance and β-cells dysfunction, play currently major role in pathogenesis of GDM. These elements are influenced by the amount of adipose tissue present before and/or during the pregnancy. Consequently, adipokines (adiponectin (APN), leptin (LPT), adipocyte fatty acid-binding protein, resistin, visfatin, omentin, vaspin, apelin, chemerin) secreted by adipose tissue, may contribute directly and/or indirectly, through the enhancement of chronic inflammation, aggravating insulin resistance and promoting GDM onset. This review aims to outline the potential physiopathological and prognostic role in GDM of adipokines, mainly APN and LPT.

First-trimester proteomic profiling identifies novel predictors of gestational diabetes mellitus

Background

Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse outcomes including preeclampsia, caesarean section, macrosomia, neonatal morbidity and future development of type 2 diabetes in both mother and child. Current selective screening strategies rely on clinical risk factors such as age, family history of diabetes, macrosomia or GDM in a previous pregnancy, and they possess a relatively low specificity. Here we hypothesize that novel first trimester protein predictors of GDM can contribute to the current selective screening strategies for early and accurate prediction of GDM, thus allowing for timely interventions.

Methods

A proteomics discovery approach was applied to first trimester sera from obese (BMI ≥27 kg/m²) women (n = 60) in a nested case-control study design, utilizing tandem mass tag labelling and tandem mass spectrometry. A subset of the identified protein markers was further validated in a second set of serum samples (n = 210) and evaluated for their contribution as predictors of GDM in relation to the maternal risk factors, by use of logistic regression and receiver operating characteristic analysis.

Results

Serum proteomic profiling identified 25 proteins with significantly different levels between cases and controls. Three proteins; afamin, serum amyloid P-component and vitronectin could be further confirmed as predictors of GDM in a validation set. Vitronectin was shown to contribute significantly to the predictive power of the maternal risk factors, indicating it as a novel independent predictor of GDM.

Conclusions

Current selective screening strategies can potentially be improved by addition of protein predictors.

Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

Role of insulin, adenosine, and adipokine receptors in the foetoplacental vascular dysfunction in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a disease of pregnancy associated with maternal and foetal hyperglycaemia and altered foetoplacental vascular function. Human foetoplacental microvascular and macrovascular endothelium from GDM pregnancy show increased maximal l-arginine transport capacity via the human cationic amino acid transporter 1 (hCAT-1) isoform and nitric oxide (NO) synthesis by the endothelial NO synthase (eNOS). These alterations are paralleled by lower maximal transport activity of the endogenous nucleoside adenosine via the human equilibrative nucleoside transporter 1 (hENT1) and activation of adenosine receptors. A causal relationship has been described for adenosine-activation of A_2A adenosine receptors, hCAT-1, and eNOS activity (i.e. the Adenosine/l-Arginine/Nitric Oxide, ALANO, signalling pathway). Insulin restores these alterations in GDM via activation of insulin receptor A (IR-A) form in the macrovascular but IR-A and IR-B forms in the microcirculation of the human placenta. Adipokines are secreted from adipocytes influencing the foetoplacental metabolic and vascular function. Various adipokines are dysregulated in GDM, with adiponectin and leptin playing major roles. Abnormal plasma concentration of these adipokines and the activation or their receptors are involved in the pathophysiology of GDM. However, involvement of adipokines, adenosine, and insulin receptors and membrane transporters in the aetiology of this disease of pregnancy is unknown. This review focuses on the pathophysiology of insulin and adenosine receptors and l-arginine and adenosine membranes transporters giving an overview of the key adipokines leptin and adiponectin in the foetoplacental vasculature in GDM. This article is part of a Special Issue entitled: Membrane Transporters and Receptors in Pregnancy Metabolic Complications edited by Luis Sobrevia.

Study on the correlation between the changes of TNFR1, TNF-α, and adiponectin in patients with gestational diabetes mellitus and insulin resistance

Gestational diabetes mellitus (GDM) refers to pregnant women with impaired glucose tolerance, which could bring high risk to the mother and fetus. However, the early diagnosis and treatment of GDM remained unclear. In this study, 60 patients with GDM were selected as the research group and 50 healthy pregnant women as the control group. Tumor necrosis factor receptor 1 (TNFR1), tumor necrosis factor-α (TNF-α), and adiponectin (ADP) in the serum were measured by enzyme-linked immunosorbent assays (ELISAs). The levels of fasting blood glucose (FBG), fasting insulin (FINS), and glycosylated hemoglobin (HbA1c) were also detected to calculate homeostasis model assessment insulin resistance index (HOMA-IR) and pancreatic β-cell function index (HOMA-HBCl). Compared with the control group, the serum levels of TNFR1, TNF-α, and HbA1c in research group were significantly increased ( P < 0.05), while ADP showed lower levels ( P < 0.01). Furthermore, FBG, FINS, and HOMA-IR were evidently increased ( P < 0.05), while homeostasis model assessment insulin secretion index (HOMA-β) and insulin sensitivity index (ISI) were decreased ( P < 0.05) in research group. TNFR and TNF-α were positively correlated with FBG, FINS, and HOMA-IR ( P < 0.05). In addition, there was a significant negative correlation between ADP and FINS and HOMA-IR ( P < 0.01). From logistic regression analysis, age, gestational age, FBG, FINS, TNFR1, TNF-α, and ADP ( P < 0.05) were shown to be risk factors to affect the function of islet β-cells. In conclusion, the high levels of TNFR1 and TNF-α and the low levels of ADP in the second trimester of pregnancy are the risk factors of GDM, which are related to the insulin resistance and impaired pancreatic β-cell function.

Effects of maternal obesity on maternal and fetal plasma concentrations of adiponectin and expression of adiponectin and its receptor genes in cotyledonary and adipose tissues at mid- and late-gestation in sheep

Adiponectin potentially influences fetal weight by altering insulin signaling and trans-placental amino acid and glucose transporters. The objective of this study was to determine how maternal obesity influences maternal and fetal plasma concentrations of adiponectin, expression of fetal adiponectin, its receptors, and adipogenic genes at mid- and late-gestation. Blood samples and tissues were collected from obese and control multiparous pregnant ewes at day 75 or 135 of gestation. Although day of gestation or maternal obesity did not influence (P >  0.6) maternal plasma concentrations of adiponectin, fetal weight was increased (P <  0.001) and adiponectin tended to decrease (P =  0.10) at mid-gestation in fetuses from obese ewes. Differences were not apparent at late-gestation (P > 0.70). Relative abundance of adiponectin (P =  0.01), AdipoR2 (P =  0.04) and PPARγ (P =  0.01) mRNA was less at mid-gestation in fetal adipose tissue from obese mothers. By late gestation, maternal obesity tended to associated with a decrease in relative abundance of adiponectin (P =  0.09) and SREBF1 (P =  0.10) mRNA in fetal adipose tissue. Maternal obesity did not influence (P ≥  0.20) the relative abundance of adiponectin, AdipoR1 and AdipoR2 mRNA in cotyledonary tissue at mid or late- gestation. In conclusion, maternal obesity in sheep influences relative abundance of fetal adipose tissue mRNA for adiponectin and adipogenic, as well as plasma concentrations of total adiponectin. Although adiposity in pregnant ewes did not influence maternal adiponectin, maternal obesity potentially influenced fetal adipogenesis by altering the abundance of adiponectin, PPARγ and SREBF1 mRNA in fetal adipose tissue.

PPARs and Metabolic Disorders Associated with Challenged Adipose Tissue Plasticity

Peroxisome proliferator-activated receptors (PPARs) are members of a family of nuclear hormone receptors that exert their transcriptional control on genes harboring PPAR-responsive regulatory elements (PPRE) in partnership with retinoid X receptors (RXR). The activation of PPARs coordinated by specific coactivators/repressors regulate networks of genes controlling diverse homeostatic processes involving inflammation, adipogenesis, lipid metabolism, glucose homeostasis, and insulin resistance. Defects in PPARs have been linked to lipodystrophy, obesity, and insulin resistance as a result of the impairment of adipose tissue expandability and functionality. PPARs can act as lipid sensors, and when optimally activated, can rewire many of the metabolic pathways typically disrupted in obesity leading to an improvement of metabolic homeostasis. PPARs also contribute to the homeostasis of adipose tissue under challenging physiological circumstances, such as pregnancy and aging. Given their potential pathogenic role and their therapeutic potential, the benefits of PPARs activation should not only be considered relevant in the context of energy balance-associated pathologies and insulin resistance but also as potential relevant targets in the context of diabetic pregnancy and changes in body composition and metabolic stress associated with aging. Here, we review the rationale for the optimization of PPAR activation under these conditions.

Adherence to the Mediterranean Diet and Serum Adiponectin Levels in Pregnancy: Results from a Cohort Study in Normal Weight Caucasian Women

The Mediterranean Diet (MedDiet) is significantly associated with anti-inflammatory effects and a favorable health outcome. During pregnancy, both inflammatory changes and oxidative balance are essential for a successful outcome, while an unbalanced inflammatory response can be a key mediator of obstetrical syndromes. The aim of this study is to investigate the adherence to MedDiet during pregnancy in the 1st and in the 3rd trimester, and to test whether the adherence was associated with serum adiponectin levels. The study was carried out on 99 normal weight Caucasian women. The adherence to MedDiet was measured by a 13-point Mediterranean scale. The whole sample scored 7.2 ± 1.5, with no difference between first and third trimester (p = 0.7). Critical points were: fruit < 3 servings/day in 77% of the sample, beans < 3 times/week in 89%, fish < 2 times/week in 69%, and nut weekly intake < 30 g in 75%. The serum adiponectin levels significantly decreased from the first to the third trimester (−16% ± 4%, p = 0.008), which confirms a low-grade inflammatory condition associated with advancing gestational age. The women who were in the highest tertile of the adherence to MedDiet had a lower percentage decrease, as compared with those in the lowest tertile (10% ± 11% vs. −34% ± 3%, p = 0.01). Even if in pregnancy the adiponectin levels are strongly influenced by the low-grade inflammation, the adherence to MedDiet may modulate this state.

Serum adipokines (adiponectin and resistin) correlation in developing gestational diabetes mellitus: pilot study

Adiponectin and resistin are adipose tissue-derived proteins with antagonistic actions; adiponectin has insulin sensitive properties while resistin is involved in the development of insulin resistance. We analyzed adiponectin and resistin levels in gestational diabetes mellitus (GDM) women to evaluate the association of these adipokines in a very high diabetes prevalence population. An age-matched case-control study of GDM and normal pregnant women in Saudi population. We recruited 90 pregnant women at 24-32 weeks of gestation. Glucose levels (fasting, 1, 2, and 3 h) and lipid parameters (cholesterol, triglyceride, HDL cholesterol, LDL cholesterol) were measured. Serum adiponectin and resistin levels were analyzed using Randox evidence biochip analyzer. Pearson's correlation coefficient was used to determine the association of adiponectin and resistin with GDM risk factors. GDM women showed significantly low adiponectin and high resistin levels when compared with control group. Pearson's correlation analysis of adiponectin and resistin in all the subjects with various GDM risk factors showed a negative association of adiponectin (r = -0.32, p = .05) and a positive correlation of resistin (r = 0.41, p = .01) with LDL cholesterol. This study analyzes adiponectin and resistin levels together, as accumulating evidences shows that these are involved in the pathophysiology of GDM. This is going to help to determine in conjunction with traditional risk factors the incremental value of circulating adiponectin and resistin in developing GDM.

The Emerging Role of Biomarkers in the Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication of pregnancy; its rising incidence is a result of increased maternal obesity and older maternal age together with altered diagnostic criteria identifying a greater proportion of pregnant women with GDM. Its consequences are far-reaching, associated with poorer maternal and neonatal outcomes compared to non-GDM pregnancies, and GDM has implications for metabolic health in both mother and offspring. Objective markers to identify women at high risk for the development of GDM are useful to target therapy and potentially prevent its development. Established clinical risk factors for GDM include overweight/obesity, age, ethnicity, and family history of diabetes, though they lack specificity for its development. The addition of biomarkers to predictive models of GDM may improve the ability to identify women at risk of GDM prior to its development. These biomarkers reflect the pathophysiologic mechanisms of GDM involving insulin resistance, chronic inflammation, and altered placental function. In addition, the role of epigenetic changes in GDM pathogenesis highlights the complex interplay between genetic and environmental factors, potentially offering further refinement of the prediction of GDM risk. In this review, we will discuss the clinical challenges associated with the diagnosis of GDM and its current pathophysiologic basis, giving rise to potential biomarkers that may aid in its identification. While not yet validated for clinical use, we explore the possible clinical role of biomarkers in the future. We also explore novel diagnostic tools, including high throughput methodologies, that may have potential future application in the identification of women with GDM.

Disparity in fetal growth between twin and singleton gestation: the role of adipokines

OBJECTIVE

Twin pregnancies are characterized by unique pattern of attenuated fetal weight gain during late gestation compared with singleton gestation. The mechanism(s) responsible for regulating twin growth has not yet elucidated. Leptin and adiponectin are two adipocytokines implicated in metabolism and energy balance of fetuses, newborns and adults. Moreover, these hormones have been suggested to play a role in fetal growth. The objective of the study was to determine cord blood adiponectin and leptin in twins and singletons, with and without growth impairment.

STUDY DESIGN

This was a case-control study. It included two groups of newborns, matched for gestational age and birth weight percentile: singleton (n=60 newborns) and twins (n=44 newborns). Adiponectin and leptin were determined in cord blood, and compared between the groups according to clinical and demographic characteristics. Non-parametric and parametric statistical methods were employed.

RESULTS

Median adiponectin and leptin concentrations were lower in twins vs singletons (P<0.001 for both comparisons). Among small for gestational age newborns (SGA), median concentration of adiponectin (P=0.04), but not leptin (P=0.1), was lower in twins compared to singletons. In pooled analysis (singleton plus twins), cord blood adiponectin and leptin were strongly correlated with gestational age (P<0.001 and P=0.005, respectively) and birth weight (P<0.001 and P<0.001, respectively). Regression analysis revealed that plurality (P=0.02) was significantly and independently associated with cord blood adiponectin concentrations, after adjustment for confounding variables. Similar regression in which leptin was the independent variable revealed that only birth weight (P=0.01) was significantly and independently associated with cord blood leptin concentrations.

CONCLUSIONS

Twin pregnancies are associated with lower cord blood concentrations of adiponectin and leptin compared with singleton gestations. However, only cord blood adiponectin, but not leptin, was lower in SGA neonates. Collectively, these data suggest that adiponectin may be implicated in the mechanism accounting for the growth disparity between twins and singletons.

Development of Multimarker Diagnostic Models from Metabolomics Analysis for Gestational Diabetes Mellitus (GDM)

Although metabolomics are desirable to understand the pathophysiology of gestational diabetes mellitus (GDM), comprehensive metabolomic studies of GDM are rare. We aimed to offer a holistic view of metabolites alteration in GDM patients and investigate the possible multimarker models for GDM diagnosis. Biochemical parameters and perinatal data of 131 GDM cases and 138 controls were collected. Fasting serum samples at 75 g oral glucose tolerance test were used for metabolites by ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry, ultra performance liquid chromatography-triple triple-quadrupole-mass spectrometry and gas chromatography- time-of- flight mass spectrometry platforms. Significant changes were observed in free fatty acids, bile acids, branched chain amino acids, organic acids, lipids and organooxygen compounds between two groups. In receiver operating characteristic (ROC) analysis, different combinations of candidate biomarkers and metabolites in multimarker models achieved satisfactory discriminative abilities for GDM, with the values of area under the curve (AUC) ranging from 0.721 to 0.751. Model consisting of body mass index (BMI), retinol binding protein 4 (RBP4), n-acetylaspartic acid and C16:1 (cis-7) manifested the best discrimination [AUC 0.751 (95% CI: 0.693-0.809), p < 0.001], followed by model consisting of BMI, Cystatin C, acetylaspartic acid and 6,7-diketoLCA [AUC 0.749 (95% CI: 0.691-0.808), p < 0.001]. Metabolites alteration reflected disorders of glucose metabolism, lipid metabolism, amino acid metabolism, bile acid metabolism as well as intestinal flora metabolism in GDM state. Multivariate models combining clinical markers and metabolites have the potential to differentiate GDM subjects from healthy controls.

Effect of multiparity and ethnicity on the risk of development of diabetes: a large population-based cohort study

AIMS

To investigate the relationship between increasing parity and diabetes in a large, population-based cohort, and to examine if this relationship is different among high-risk ethnic groups.

METHODS

A population-based, retrospective cohort study was performed in 738 440 women aged 18-50 years, who delivered babies in Ontario between 1 April 2002 and 31 March 2011. Diabetes incidence postpartum was calculated for each parity and ethnic group. A multivariable analysis of the effect of parity and ethnicity on the incidence of diabetes was performed using a Cox proportional hazards model, adjusting for confounders.

RESULTS

The diabetes incidence rate per 1000 person-years was 3.69 in women with 1 delivery, 4.12 in women with 3 deliveries and 7.62 in women with ≥5 deliveries. Women with ≥3 deliveries had a higher risk of developing diabetes compared with women with 1 delivery [adjusted hazard ratios 1.06 (95% CI 1.01-1.11) for 3 deliveries, 1.33 (95% CI 1.25-1.43) for 4 deliveries and 1.53 (95% CI 1.41-1.66) for ≥5 deliveries). A similar rise in risk could be seen in Chinese and South-Asian women, with the most influence in Chinese women [hazard ratio 4.59 (95% CI 2.36-8.92) for ≥5 deliveries].

CONCLUSIONS

There was a positive and graded relationship between increasing parity and risk of development of diabetes. The influence of parity was seen in all ethnicities. This association may be partly related to increasing weight gain and retention with increasing parity, or deterioration in β-cell function. This merits further exploration.

Roles of Inflammation and Depression in the Development of Gestational Diabetes

Inflammation, the body's response to harmful external agents, has long been found to be associated with depressive symptoms. The relationship between inflammation and depression is well established in the general population of people with depression, but is less so among perinatal women. Depression in the perinatal period is a common disorder, however available data do not indicate that there is a specific inflammatory picture associated with perinatal depression. We suggest that perinatal depression may be a heterogeneous construct, and that inflammation may be relevant to it in the context of other inflammatory morbidities of pregnancy. In this review we explore the available support for the hypothesis that inflammation associated with depression can represent a precipitating insult for the development of gestational diabetes, a known inflammatory morbidity of pregnancy.

Serum adiponectin levels in gestational diabetes mellitus

INTRODUCTION

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy.^[1] Pregnancy is a unique situation in which there is a physiological temporary increase in insulin resistance (IR). The mechanisms responsible for the gestational-induced IR are not completely understood. The current study was undertaken to compare adiponectin levels during 24-28 weeks period of gestation in drug-naive newly diagnosed GDM women with a cohort of normoglycemic pregnant women.

SUBJECTS AND METHODS

A total of 47 pregnant women in the age group of 18-40 years were included in this cross-sectional study, of which 13 were GDM cases and 34 were normoglycemic controls. Serum adiponectin level was analyzed by enzyme-linked immunosorbent assay.

RESULTS

The mean adiponectin level was 16.92 ng/ml (standard deviation [SD] = 2.78) and 19.38 ng/ml (SD = 2.71) in case and control groups, respectively, and the difference was found to be statistically significant (P = 0.008).

CONCLUSION

Our study demonstrated decreased serum adiponectin levels in women with GDM when compared with age- and body mass index-matched euglycemic pregnant women.

Characterization of visceral and subcutaneous adipose tissue transcriptome in pregnant women with and without spontaneous labor at term: implication of alternative splicing in the metabolic adaptations of adipose tissue to parturition

OBJECTIVE

The aim of this study was to determine gene expression and splicing changes associated with parturition and regions (visceral vs. subcutaneous) of the adipose tissue of pregnant women.

STUDY DESIGN

The transcriptome of visceral and abdominal subcutaneous adipose tissue from pregnant women at term with (n=15) and without (n=25) spontaneous labor was profiled with the Affymetrix GeneChip Human Exon 1.0 ST array. Overall gene expression changes and the differential exon usage rate were compared between patient groups (unpaired analyses) and adipose tissue regions (paired analyses). Selected genes were tested by quantitative reverse transcription-polymerase chain reaction.

RESULTS

Four hundred and eighty-two genes were differentially expressed between visceral and subcutaneous fat of pregnant women with spontaneous labor at term (q-value <0.1; fold change >1.5). Biological processes enriched in this comparison included tissue and vasculature development as well as inflammatory and metabolic pathways. Differential splicing was found for 42 genes [q-value <0.1; differences in Finding Isoforms using Robust Multichip Analysis scores >2] between adipose tissue regions of women not in labor. Differential exon usage associated with parturition was found for three genes (LIMS1, HSPA5, and GSTK1) in subcutaneous tissues.

CONCLUSION

We show for the first time evidence of implication of mRNA splicing and processing machinery in the subcutaneous adipose tissue of women in labor compared to those without labor.

First-trimester multimarker prediction of gestational diabetes mellitus using targeted mass spectrometry

AIMS/HYPOTHESIS

Gestational diabetes mellitus (GDM) is associated with an increased risk of pre-eclampsia, macrosomia and the future development of type 2 diabetes mellitus in both mother and child. Although an early and accurate prediction of GDM is needed to allow intervention and improve perinatal outcome, no single protein biomarker has yet proven useful for this purpose. In the present study, we hypothesised that multimarker panels of serum proteins can improve first-trimester prediction of GDM among obese and non-obese women compared with single markers.

METHODS

A nested case-control study was performed on first-trimester serum samples from 199 GDM cases and 208 controls, each divided into an obese group (BMI ≥27 kg/m(2)) and a non-obese group (BMI <27 kg/m(2)). Based on their biological relevance to GDM or type 2 diabetes mellitus or on their previously reported potential as biomarkers for these diseases, a number of proteins were selected for targeted nano-flow liquid chromatography (LC) MS analysis. This resulted in the development and validation of a 25-plex multiple reaction monitoring (MRM) MS assay.

RESULTS

After false discovery rate correction, six proteins remained significantly different (p<0.05) between obese GDM patients (n=135) and BMI-matched controls (n=139). These included adiponectin, apolipoprotein M and apolipoprotein D. Multimarker models combining protein levels and clinical data were then constructed and evaluated by receiver operating characteristic (ROC) analysis. For the obese, non-obese and all GDM groups, these models achieved marginally higher AUCs compared with adiponectin alone.

CONCLUSIONS/INTERPRETATION

Multimarker models combining protein markers and clinical data have the potential to predict women at a high risk of developing GDM.

Adiponectin, C-reactive protein, fibrinogen and tissue plasminogen activator antigen levels among glucose-intolerant women with and without histories of gestational diabetes

AIM

To examine concentrations of biomarkers (adiponectin, C-reactive protein, fibrinogen and tissue plasminogen-activator antigen) associated with glucose homeostasis and diabetes risk by history of gestational diabetes (GDM).

METHODS

We conducted a secondary analysis of the Diabetes Prevention Program, a randomized trial of lifestyle intervention or metformin for diabetes prevention. At baseline, participants were overweight and had impaired glucose tolerance. Biomarkers at baseline and 1 year after enrolment were compared between parous women with (n = 350) and without histories of GDM (n = 1466). Cox proportional hazard models evaluated whether history of GDM was associated with diabetes risk, after adjustment for baseline biomarker levels as well as for change in biomarker levels, demographic factors and anthropometrics.

RESULTS

At baseline, women with histories of GDM had lower adiponectin (7.5 μg/ml vs. 8.7 μg/ml; p < 0.0001) and greater log C-reactive protein (-0.90 mg/l vs. -0.78 mg/l, p = 0.04) levels than women without histories of GDM, but these associations did not persist after adjustment for demographic factors. Fibrinogen and tissue plasminogen-activator antigen were similar between women with and without histories of GDM. Women with and without histories of GDM had a similar pattern of changes in biomarkers within randomization arm. Adjustment for age, race/ethnicity, baseline weight, change in weight, baseline biomarker level and change in biomarker level did not significantly alter the association between history of GDM, and diabetes risk.

CONCLUSIONS

Among women with impaired glucose tolerance, biomarkers in women with and without histories of GDM are similar and respond similarly to lifestyle changes and metformin. Adjustment for biomarker levels did not explain the higher risk of diabetes observed in women with histories of GDM.

Characterization of Visceral and Subcutaneous Adipose Tissue Transcriptome and Biological Pathways in Pregnant and Non-Pregnant Women: Evidence for Pregnancy-Related Regional-Specific Differences in Adipose Tissue

Objective

The purpose of this study was to compare the transcriptome of visceral and subcutaneous adipose tissues between pregnant and non-pregnant women.

Study Design

The transcriptome of paired visceral and abdominal subcutaneous adipose tissues from pregnant women at term and matched non-pregnant women (n = 11) was profiled with the Affymetrix Human Exon 1.0 ST array. Differential expression of selected genes was validated with the use of quantitative reverse transcription–polymerase chain reaction.

Results

Six hundred forty-four transcripts from 633 known genes were differentially expressed (false discovery rate (FDR) <0.1; fold-change >1.5), while 42 exons from 36 genes showed differential usage (difference in FIRMA scores >2 and FDR<0.1) between the visceral and subcutaneous fat of pregnant women. Fifty-six known genes were differentially expressed between pregnant and non-pregnant subcutaneous fat and three genes in the visceral fat. Enriched biological processes in the subcutaneous adipose tissue of pregnant women were mostly related to inflammation.

Conclusion

The transcriptome of visceral and subcutaneous fat depots reveals pregnancy-related gene expression and splicing differences in both visceral and subcutaneous adipose tissue. Furthermore, for the first time, alternative splicing in adipose tissue has been associated with regional differences and human parturition.

Effect of maternal diabetes on the embryo, fetus, and children: congenital anomalies, genetic and epigenetic changes and developmental outcomes

INTRODUCTION

Pregestational and gestational diabetes mellitus (PGDM; GDM) are significant health concerns because they are associated with an increased rate of malformations and maternal health complications.

METHODS

We reviewed the data that help us to understand the effects of diabetes in pregnancy.

RESULTS

Diabetic embryopathy can affect any developing organ system, but cardiovascular and neural tube defects are among the most frequent anomalies. Other complications include preeclampsia, preterm delivery, fetal growth abnormalities, and perinatal mortality. Neurodevelopmental studies on offspring of mothers with diabetes demonstrated increased rate of Gross and Fine motor abnormalities, of Attention Deficit Hyperactivity Disorder, learning difficulties, and possibly also Autism Spectrum Disorder. The mechanisms underlying the effects of maternal hyperglycemia on the developing fetus may involve increased oxidative stress, hypoxia, apoptosis, and epigenetic changes. Evidence for epigenetic changes are the following: not all progeny are affected and not to the same extent; maternal diet may influence pregnancy outcomes; and maternal diabetes alters embryonic transcriptional profiles and increases the variation between transcriptomic profiles as a result of altered gene regulation. Research in animal models has revealed that maternal hyperglycemia is a teratogen, and has helped uncover potential therapeutic targets which, when blocked, can mitigate or ameliorate the negative effects of diabetes on the developing fetus.

CONCLUSIONS

Tight metabolic control, surveillance, and labor management remain the cornerstone of care for pregnant women with diabetes, but advances in the field indicate that new treatments to protect the mother and baby are not far from becoming clinical realities.

Maternal circulating concentrations of tumor necrosis factor-alpha, leptin, and adiponectin in gestational diabetes mellitus: a systematic review and meta-analysis

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications. Inflammation may play a role in the pathogenesis of GDM. We performed a systematic review and meta-analysis to determine whether maternal serum concentration of tumor necrosis factor-alpha (TNF-α), leptin, and adiponectin were associated with GDM. A systematic search of PubMed and Medline was undertaken. In total, 27 trials were evaluated by meta-analyses using the software Review Manager 5.0. The results showed that maternal TNF-α (P = 0.0003) and leptin (P < 0.00001) concentrations were significantly higher in GDM patients versus controls. However, maternal adiponectin (P < 0.00001) concentration was significantly lower in GDM patients compared with controls. Subgroup analysis taking in consideration the effect of obesity on maternal adipokine levels showed that circulating levels of TNF-α and leptin remained elevated in GDM patients compared to their body mass index (BMI) matched controls, and adiponectin level remained depressed in GDM individuals. Our findings strengthen the clinical evidence that GDM is accompanied by exaggerated inflammatory responses.

Adipokines in gestational diabetes

Gestational diabetes is characterised by glucose intolerance with onset or first recognition during pregnancy. The disease shows facets of the metabolic syndrome including obesity, insulin resistance, and dyslipidaemia. Adipokines are a group of proteins secreted from adipocytes, which are dysregulated in obesity and contribute to metabolic and vascular complications. Recent studies have assessed the role of various adipokines including leptin, adiponectin, tumour necrosis factor α (TNFα), adipocyte fatty acid-binding protein (AFABP), retinol-binding protein 4 (RBP4), resistin, NAMPT, SERPINA12, chemerin, progranulin, FGF-21, TIMP1, LCN2, AZGP1, apelin (APLN), and omentin in gestational diabetes. This Review provides an overview of these key adipokines, their regulation in, and potential contribution to gestational diabetes. Based on the evidence so far, the adipokines adiponectin, leptin, TNFα, and AFABP seem to be the most probable candidates involved in the pathophysiology of gestational diabetes.

Diabetes and pregnancy: perspectives from Asia

There has been a marked increase in the prevalence of diabetes in Asia over recent years. Diabetes complicating pregnancy, in particular gestational diabetes, has also increased markedly in the region. Multi-ethnic studies have highlighted the increased risk of gestational diabetes mellitus among the different Asian populations. Prevalence of gestational diabetes in Asian countries varies substantially according to the screening strategy and diagnostic criteria applied, and ranges from 1% to 20%, with evidence of an increasing trend over recent years. The International Association for Diabetes in Pregnancy Study group criteria have been adopted by some Asian countries, although they present significant challenges in implementation, especially in low-resource settings. Studies on offspring of mothers with gestational diabetes have reported adverse cardiometabolic profiles and increased risk of diabetes and obesity. Gestational diabetes is likely to be a significant factor contributing to the epidemic of diabetes and other non-communicable diseases in the Asian region. In recognition of this, several large-scale prevention and intervention programmes are currently being implemented in different Asian countries in order to improve glucose control during pregnancy, as well as overall maternal health. Lessons emerging from gestational diabetes studies in Asia may help inform and provide insights on the overall burden and treatment strategies to target gestational diabetes, with the ultimate aim to reduce its adverse short- and long-term consequences.

Amniotic fluid insulin and C-peptide as predictive markers for fetal macrosomia, birth injuries, and delivery complications?

Background

Gestational diabetes mellitus (GDM) occurs in 3–5% of all pregnancies. GDM increases both maternal and fetal risks, causes fetal macrosomia, and hence increases the rates of caesarean sections and delivery complications such as shoulder dystocia. An early predictive marker and consequent early treatment could be beneficial, so amniotic fluid insulin and C-peptide have been examined in several studies. Increased amniotic fluid insulin in early amniocentesis between the 14^th and 20^th gestational week predicted a later GDM. A potential direct association with fetal macrosomia remains to be determined.

Material/Methods

This retrospective study investigated amniotic fluid insulin/C-peptide from amniocenteses between 14 and 20 weeks of gestation in correlation with fetal birth weight, type of delivery, and complications. To focus on effects of fetal hyperinsulinism apart from therapeutic confounders, we included patients who did not participate in GDM screening. Insulin and C-peptide were measured in 144 samples of frozen amniotic fluid. Birth weight, type of delivery, complications, and birth injuries were noted.

Results

Birth weights ranged from 760 g to 4410 g with a mean weight of 3424 g at an average of 40 weeks gestation. The mean amniotic fluid insulin was 4.36 μU/ml and the mean C-peptide concentration was 0.076 ng/ml. There was no correlation between amniotic fluid insulin or C peptide and birth weight, type of delivery, complications, and birth injuries.

Conclusions

Amniotic fluid insulin and C-peptide are unsuitable as predictive marker for fetal macrosomia, type of delivery, complications, or birth injuries.

Adipocytokines during pregnancy and postpartum in women with gestational diabetes and healthy controls

BACKGROUND

This study aims to explore the changes in maternal serum adipocytokines during pregnancy and post partum in normal and complicated with gestational diabetes (GDM) pregnancies and to investigate the relationship between serum adipocytokines and some of major metabolic parameters.

MATERIALS AND METHODS

236 pregnant women (127 with GDM and 109 control group) and 50 postpartum women (30 with GDM during pregnancy and 20 controls). Using ELISA and EIA kits, serum levels of adipocytokines were tested during pregnancy and post partum. Maternal adipocytokines levels were correlated with some metabolic parameters.

RESULTS

Women with GDM had lower values of adiponectin and higher values of leptin during pregnancy (p<0.001; 0.0001) and post partum (p<0.002; 0.0001). Serum apelin was significantly lower in GDM group (p<0.009). However, we did not find significance for resistin (p<0.317) and apelin (p<0.218). Positive correlation for leptin and negative for adiponectin was found for pre-pregnancy and pregnancy body mass index, glycated hemoglobin and homeostasis model assessment of insulin resistance index. Using cut point of 8.2 μg/ml for adiponectin and 28.7 ng/ml for leptin could exclude GDM with a sensitivity of 83.6%/81.2% and specificity of 56.6%/64.2% (area under the curve 0.702 and 0.827).

CONCLUSION

There are constant differences in adiponectin and leptin levels between GDM and control group during pregnancy and post partum. Apelin was decreased in our GDM group and no differences were found for resistin and visfatin. Further studies are required to verify the mechanism of this alteration and whether the adipocytokines can be predictors for GDM at an early stage of pregnancy.

Low prepregnancy adiponectin concentrations are associated with a marked increase in risk for development of gestational diabetes mellitus

OBJECTIVE

To examine whether circulating total and high-molecular weight (HMW) adiponectin concentrations, measured before pregnancy, are associated with subsequent risk of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

This was a nested case-control study among women who participated in the Kaiser Permanente Northern California Multiphasic Health Check-up exam (1984-1996) with a serum sample obtained and who had a subsequent pregnancy (1984-2009). Eligible women were free of recognized diabetes. Case subjects were the 256 women who developed GDM. Two control subjects were selected for each case and matched for year of blood draw, age at exam, age at pregnancy, and number of intervening pregnancies.

RESULTS

Compared with the highest quartile of adiponectin, the risk of GDM increased with decreasing quartile (odds ratio [OR] 1.5 [95% CI 0.7-2.9], 3.7 [1.9-7.2], and 5.2 [2.6-10.1]; P(trend) <0.001) after adjustment for family history of diabetes, BMI, parity, race/ethnicity, cigarette smoking, and glucose and insulin concentrations. Similar estimates were observed for HMW (P(trend) <0.001). The combined effects of having total adiponectin levels below the median (<10.29 mg/mL) and being overweight or obese (BMI ≥25.0 kg/m(2)) were associated with a sevenfold increased risk of GDM compared with normal-weight women with adiponectin levels above the median (OR 6.7 [95% CI 3.6-12.5]).

CONCLUSIONS

Prepregnancy low adiponectin concentrations, a marker of decreased insulin sensitivity and altered adipocyte endocrine function, is associated with reduced glucose tolerance during pregnancy and may identify women at high risk for GDM to target for early intervention.

Potential mechanisms of exercise in gestational diabetes

Gestational diabetes mellitus (GDM) is defined as glucose intolerance first diagnosed during pregnancy. This condition shares same array of underlying abnormalities as occurs in diabetes outside of pregnancy, for example, genetic and environmental causes. However, the role of a sedentary lifestyle and/or excess energy intake is more prominent in GDM. Physically active women are less likely to develop GDM and other pregnancy-related diseases. Weight gain in pregnancy causes increased release of adipokines from adipose tissue; many adipokines increase oxidative stress and insulin resistance. Increased intramyocellular lipids also increase cellular oxidative stress with subsequent generation of reactive oxygen species. A well-planned program of exercise is an important component of a healthy lifestyle and, in spite of old myths, is also recommended during pregnancy. This paper briefly reviews the role of adipokines in gestational diabetes and attempts to shed some light on the mechanisms by which exercise can be beneficial as an adjuvant therapy in GDM. In this regard, we discuss the mechanisms by which exercise increases insulin sensitivity, changes adipokine profile levels, and boosts antioxidant mechanisms.

Association between adiponectin and tumor necrosis factor-alpha levels at eight to fourteen weeks gestation and maternal glucose tolerance: the Parity, Inflammation, and Diabetes Study

OBJECTIVE

Inflammation may influence gestational hyperglycemia, but to date, the data from observational studies is largely limited to results from the third trimester of pregnancy. Our objective was to evaluate first trimester adipocytokine levels. We sought to determine whether first trimester adiponectin and tumor necrosis factor-alpha (TNF)-alpha concentrations were independently associated and predictive of maternal glucose tolerance, as measured by the 1-hour glucose challenge test (GCT), after adjustment for maternal lifestyle behaviors and body mass index (BMI).

MATERIAL AND METHODS

Prospective study of pregnant women (n=211) enrolled in the Parity, Inflammation, and Diabetes Study. Nonfasting serum levels of adiponectin and TNF-r2 were measured at 8-14 weeks of pregnancy. GCT results were abstracted from electronic prenatal records. Multiple linear regression models were developed to determine the association of adiponectin and TNF-r2 levels with response to the GCT, adjusting for demographics, pregravid dietary intake and physical activity, first trimester BMI, and gestational weight gain.

RESULTS

At baseline, higher adiponectin concentrations were inversely and statistically significantly associated with maternal response to the GCT [regression coefficient (β) -0.68; 95% confidence interval (CI): -1.29, -0.06). Adjustment for lifestyle factors did not alter the association of adiponectin with the GCT (β -0.74; 95% CI: -1.43, -0.05). After adjustment for first trimester BMI, the association of adiponectin was attenuated and no longer significant (β -0.46; 95% CI: -1.15, 0.24). TNF-r2 levels were not associated with the GCT (β -0.003; 95% CI: -0.011, 0.005).

CONCLUSIONS

First trimester adiponectin levels are not predictive of the 1-hour GCT response, but may be a marker for the effect of maternal BMI on glucose response to the GCT.

Maternal and fetal leptin, adiponectin levels and associations with fetal insulin sensitivity

OBJECTIVE

It remains uncertain whether leptin and adiponectin levels are correlated in maternal vs. fetal circulations. Little is known about whether leptin and adiponectin affect insulin sensitivity during fetal life.

DESIGN AND METHODS

In a prospective singleton pregnancy cohort (n = 248), we investigated leptin and adiponectin concentrations in maternal (at 24-28 and 32-35 weeks of gestation) and fetal circulations, and their associations with fetal insulin sensitivity (glucose/insulin ratio, proinsulin level).

RESULTS

Comparing concentrations in cord vs. maternal blood, leptin levels were 50% lower, but adiponectin levels more than doubled. Adjusting for gestational age at blood sampling, consistent and similar positive correlations (correlation coefficients: 0.31-0.34, all P < 0.0001) were observed in leptin or adiponectin levels in maternal (at 24-28 or 32-25 weeks of gestation) vs. fetal circulations. For each SD increase in maternal plasma concentration at 24-28 weeks, cord plasma concentration increased by 12.7 (95% confidence interval 6.8-18.5) ng/ml for leptin, and 2.9 (1.8-4.0) µg/ml for adiponectin, respectively (adjusted P < 0.0001). Fetal insulin sensitivity was negatively associated with cord blood leptin (each SD increase was associated with a 5.4 (2.1-8.7) mg/dl/µU/ml reduction in cord plasma glucose/insulin ratio, and a 5.6 (3.9, 7.4) pmol/l increase in proinsulin level, all adjusted P < 0.01) but not adiponectin (P > 0.4) levels). Similar associations were observed in nondiabetic full-term pregnancies (n = 211).

CONCLUSIONS

The results consistently suggest a maternal impact on fetal leptin and adiponectin levels, which may be an early life pathway in maternal-fetal transmission of the propensity to obesity and insulin resistance.

Chemerin is present in human cord blood and is positively correlated with birthweight

OBJECTIVE

Chemerin, a novel adipokine, has been implicated in adipogenesis, inflammation, and metabolism. The aims of this study were to determine the presence of chemerin in cord blood and its association with birthweight.

STUDY DESIGN

This cross-sectional study included the following: (1) twins with (n = 24) or without (n = 28) birthweight discordancy; and (2) singletons subclassified into small-for-gestational-age (SGA; n = 18); appropriate for gestational age (AGA; n = 33); and large-for-gestational-age (LGA; n = 8). Cord blood chemerin was determined. Parametric and nonparametric statistics were used for analysis.

RESULTS

The results of the study included the following: (1) within the discordant twins group, the median chemerin concentration was significantly lower in the SGA group than in their cotwins; (2) within singletons, the median chemerin concentration was significantly higher in the LGA than the AGA newborns; and (3) the regression model revealed that chemerin was independently associated with birthweight.

CONCLUSION

Cord blood chemerin is present in cord blood and its concentrations are positively correlated with birthweight. These novel findings support a role of adipokines in fetal growth.

Role of adipokines and other inflammatory mediators in gestational diabetes mellitus and previous gestational diabetes mellitus

Previous Gestational Diabetes Mellitus (pGDM) is a common condition and has been associated with future development of Type 2 Diabetes Mellitus (T2DM) and Metabolic Syndrome (MS) in women affected. The pathogenesis and risk factors implicated in the development of these conditions later in the lives of women with pGDM are not as yet fully understood. Research has recently focused on a group of substances produced mainly by adipose tissue called adipokines, this group including, among others, adiponectin, leptin, Retinol-Binding Protein-4 (RBP-4), and resistin. These substances as well as other inflammatory mediators (CRP, IL-6, PAI-1, TNF-α) seem to play an important role in glucose tolerance and insulin sensitivity dysregulation in women with pGDM. We summarize the data available on the role of these molecules.

Adiponectin and reproduction

Adiponectin is an adipocyte-derived cytokine that acts as a major regulator of insulin sensitivity. Adiponectin deficiency can result in severe diabetes and metabolic disorders in humans. Since its discovery, our understanding of adiponectin's biological functions has expanded from insulin sensitization properties to new effects on inflammation, immunology, and human reproduction. Indeed, both obesity and excessive leanness are associated with reproductive dysfunction. The objective of this chapter is to review such biological actions and the potential roles of adiponectin on human reproduction. There is accumulative evidence for direct effects of this adipokine on the late stages of folliculogenesis and on the development of a functional placenta. In addition, clinical and genomic studies associate hypoadiponectinemia with pregnancy-related disorders, including polycystic ovarian syndrome.

Apelin levels in normal pregnancy

OBJECTIVE

Apelin is an adipokine secreted from adipose and other tissues with increased expression in obesity, role in glucose metabolism and atherosclerosis, as well as in oxidative stress. Pregnancy is considered a state of hyperlipidemia, oxidative stress and decreased insulin sensitivity. The aim of the present study is to investigate the levels of apelin in human pregnancy and its relation to insulin sensitivity.

PATIENTS AND MEASUREMENTS

One hundred and six pregnant women (24th-28th week of gestation), aged 27·9 ± 0·4 years, were compared to 106 age-matched healthy, nonpregnant women (controls). Measured parameters included serum levels of glucose, insulin, apelin, adiponectin, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL), triglycerides and oxidized LDL (ox-LDL). The body mass index (BMI) and the quantitative insulin sensitivity check index (QUICKI) were calculated as well.

RESULTS

BMI, serum lipids and insulin levels were significantly higher, whereas serum apelin and glucose levels were lower in the pregnancy group compared to the control group. There was a significant negative correlation between apelin and adiponectin, in both groups. Additionally, apelin was negatively correlated with ox-LDL and HDL-cholesterol in the pregnancy group.

CONCLUSIONS

Although strongly correlated with adiponectin, apelin cannot be used as a marker of insulin sensitivity, but it could serve as a marker of oxidative stress in pregnancy.

Third trimester plasma adiponectin and leptin in gestational diabetes and normal pregnancies

The aim of this study was to compare pregnant women with and without gestational diabetes (GDM) with regard to third trimester adiponectin, leptin and insulin resistance, as well as to investigate their relation to fetal growth and macrosomia. 134 pregnant women were enrolled in the study: 86 with GDM and 48 controls. Maternal plasma adiponectin, leptin, fasting insulin, glucose and fetal biometry were measured between 27 and 32 weeks of gestation. Birthweight and delivery data were also assessed. Adiponectin in GDM patients was lower when compared to non-diabetic women while mean leptin concentration was not different. In GDM group only mothers' weight gain until third trimester was significantly different between the groups of patients with normal and accelerated fetal growth. No correlation of adiponectin and leptin with fetal growth was shown. Mothers' weight gain until third trimester and mean fasting glucose between 33 and 34 weeks of gestation were associated with neonatal macrosomia. There were no differences in adiponectin and leptin between mothers of macrosomic and non-macrosomic neonates. Fetal growth seems not to be related to third trimester adiponectin and leptin concentrations, while increased third trimester fasting glucose may be an independent risk factor of macrosomia.

Inflammatory mediators and glucose in pregnancy: results from a subset of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study

CONTEXT

Inflammatory mediators are associated with type 2 and gestational diabetes. It is unknown whether there are associations with glucose in pregnant women with lesser degrees of hyperglycemia.

OBJECTIVE

The objective of the study was to examine associations of inflammatory mediators with maternal glucose levels and neonatal size in a subset of participants in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study.

DESIGN

Eligible pregnant women underwent a 75-g oral glucose tolerance test between 24 and 32 wk gestation, and levels of C-peptide, adiponectin, plasminogen activator inhibitor type 1 (PAI-1), C-reactive protein (CRP), and resistin were measured in fasting serum samples. Associations of inflammatory mediators with maternal glucose and with birth size were assessed using multiple linear regression analyses, adjusting for maternal body mass index (BMI), fasting C-peptide, and other potential confounders.

RESULTS

Mean levels of adiponectin declined, and PAI-1 and CRP increased across increasing levels of maternal glucose, BMI, and C-peptide. For example, for fasting plasma glucose less than 75 mg/dl and fasting plasma glucose of 90 mg/dl or greater, adiponectin was 22.5 and 17.4 μg/ml and PAI-1 was 30.9 and 34.2 ng/ml, respectively. Associations with 1- and 2-h plasma glucose remained significant for adiponectin (P<0.001), PAI-1 (P<0.05), and CRP (P<0.01) after adjustment for BMI and C-peptide. Adiponectin and CRP were inversely associated with birth weight, sum of skinfolds and percent body fat, and PAI-1 with sum of skinfolds (all P<0.05) after adjustment for confounders. Resistin was not associated with 1- or 2-h glucose or birth size.

CONCLUSION

Levels of inflammatory mediators are associated with levels of maternal glucose in pregnant women without overt diabetes.

Obesity and the placenta: A consideration of nutrient exchange mechanisms in relation to aberrant fetal growth

The obesity epidemic, including childhood obesity, is rapidly gaining strength as one of the most significant challenges to the health of the global community in the 21st Century. The proportion of women who are obese at the beginning of pregnancy is also increasing. These women and their babies are at high risk of pregnancy complications, and of programming for metabolic disease in adult life. In particular, maternal obesity is associated with aberrant fetal growth, encompassing both growth restricted and large for gestational age, or macrosomic fetuses. This article considers the potential effect of obesity and adipose tissue on placental nutrient exchange mechanisms in relation to aberrant fetal growth. The review emphasizes the dearth of work on this topic to date despite its importance to current and future healthcare of the population.